Postpress Technology 1000 Questions (121-130)

1 21. What factors need to be considered in glossy design?

There are many factors that need to be considered in the gloss design. The main factors are as follows:

(1) The quality of the paper itself has a great influence on the effect of post-printing coating. Coated papers, whiteboards, and paperboards with good surface texture and high smoothness have a better post-printing finish.

(2) Printing color sequence has an effect on the glazing effect. The first printing of a large area of ​​the background color and light color, after printing dark color and small color blocks, is conducive to the ink from the inside to fully dry. Good prints with good gloss have high gloss and strong adhesion.

(3) The paper for laminated film prints should have large surface strength, high smoothness, whiteness, low water content, uniform texture, good ink absorption, and low shrinkage. Only in this way can products with good filming effect be obtained. The high water content of the paper not only causes deformation during printing, but also causes troubles such as wrinkling, wrinkling, blistering, and delamination when the film is covered. Poor smoothness, strong ink absorption, not only affect the quality of the printing, film elbow is also easy to foam, delamination, affecting product quality. Film-covered prints are generally suitable for the use of offset papers or coated papers and whiteboard papers of 60 g or more.

(4) Printed products that require laminating, if the printing ink is thick and the area of ​​the graphic is large, it will hinder the penetration and diffusion of the adhesive, and it is difficult to adhere to the plastic film, which may cause problems such as delamination and blistering. Therefore, the ink layer should be thin (approximately 1 to 2 um) to print using an offset process.

5 film products are prone to edging. When the cover of the book is covered with a film, it should be designed to prevent waggling. If you take a glazing treatment, you don't have to design a mouthwash.

6 In the relationship of the color of the design prints, consideration should be given to whether the materials used for post-printing or laminating processes are yellowish. Only when the countermeasures are worked out in advance can the printed matter finally achieve the desired effect.

7 Ordinary ink prints covered with matt film or printed with matte ink can produce a shiny effect.

1 22. What is the processing of the three-dimensional effect of the printed surface?

Any object in space has a three-dimensional three-dimensional shape of length, width, and height. There is a front-back, left-right, and top-down relationship. However, general photographs, drawings, and prints belong to the two-dimensional plane and are not actual three-dimensional stereoscopic forms. In order to create a three-dimensional effect on the surface of the two-dimensional printed matter, the surface of the printed matter may be subjected to embossing, embossing, embossing, and other methods to produce a three-dimensional effect on the surface of the printed matter.

1 23. What is pressure bump?
Embossing, also known as embossing and embossing, is a method of printing embossed graphics using a pair of anodized concave and convex prints without printing ink (see Figure 1).

1 24. Press and emboss more applications which products of decorative processing

The embossing method is mostly used for the processing of printed matters such as trademarks, paper boxes, greeting cards, and bottle stickers. The effect is vivid and beautiful, and the three-dimensional effect is strong.

1 25. Embossing process is an interest?

The embossing process is as follows: a gravure printing system makes a convex printing and embossing printing.

1 26. What is the layout of the gravure printing layout?

On the gravure plate, the image is partly concave and the blank part is convex and on the same plane or on the arc of the same radius. There is a great disparity in the level of the graphic and blank sections.

127. What is the layout of the relief printing layout?

The blank part of the relief printing plate is concave, and the graphic part is convex and on the same plane or on the arc surface of the same radius, the level difference between the graphic part and the blank part is very different.

128. How is the gravure used for embossing made?

The gravure plate is generally made of copper plate, and the thickness is between 1 and 3 mm. The engraving tool is divided into four kinds of knives, flat knives, round knives and row knives according to different purposes. Tool width 0.3 ~ 0.5cm, length 1 Ocm, engraving depth according to the degree of pressure on the paper to not break is appropriate, the general depth of control in the thickness of about 50%. Thick paper, poor embossing and embossing effect is poor, thin paper, too deep imprint stamping fragile. Engraving two blocks of surface convergence, there must be a shallow or deep shallow slope, so as to achieve the entire printing surface and the unity of harmony, the main highlight, rich layers, strong sense of three-dimensional.

In order to improve the platemaking efficiency and reduce the labor intensity, the gravure is often produced by a combination of etching and engraving. Usually, the method of deep etching is adopted first, that is, the photosensitive material is applied to the copper plate surface, and the positive film film surface is relatively closely exposed. After that, it was immersed in a solution of ferric chloride and etched to a certain depth. Because the depth of the graphic text after etching is the same, the contour is not obvious, the level is poor, and the mouth is rough. Therefore, it is necessary to re-engrave and process. According to the specific graphic requirements, corresponding carving techniques are adopted, for example, the screen pattern is circular ( Fruits, animals, etc.) The engraving of the mouth should be rounded; if it is a text line pattern, the mouth of the mouth should be trimmed into a straight edge; in order to highlight the three-dimensional shape, the mouth of the plate is sometimes slanted.

129. How is the relief printing used for embossing?

After the embossed gravure is made, a gypsum embossing relief plate opposite to the concave pattern needs to be provided. There are two kinds of replication processes, one is a traditional plaster relief process, and the other is a new type of polymeric punch process.

1 30. How is the gypsum embossing relief used for embossing printed?

Traditional gypsum punch production process: The prepared copper (steel) gravure is stuck on the metal floor of the flat press machine, the school board, and paste on the embossing plate with yellow cardboard, and then use glue or sticky rice Slurry reconcile gypsum paste, quickly pour the gypsum onto a stencil with yellow paper, slightly spread out, spread a thin layer of paper, and prevent the gypsum powder from falling into the pattern, then cover with a layer of plastic film. , Gently brush a layer of kerosene on the gravure before embossing to prevent the plaster mold from sticking during embossing. The first time the imprinting force should be small, about the shadow can be displayed; the second imprinting, after the gravure plate is placed on a thicker whiteboard paper, when the gypsum powder is imprinted when the quick-drying, until the gypsum powder completely After curing and drying, the excess plaster around the area was removed and a gypsum embossing relief printing plate was made.

Source: "Guangdong Printing" (author / Jin Yinhe: Beizhuang Institute of Graphic Communication)